Time-point generator

ABSTRACT

A time-point generator includes a polystage multivibrator for producing pulse signals of a predetermined frequency and spacing, a logic sequencer controlled by said multivibrator, means connected to the multivibrator for changing the spacing of some of the pulses, and gating means controlled by the output of the multivibrator and by the output of the logic sequencer, the timepoint generator being disclosed as forming part of an automatic rhythm device.

United States Patent Inventor Alfred B. Freeman 20418 Seaboard Road, Malibu, Calif. 90265 Appl. No. 7,522 Filed Feb. 2, 1970 Patented Dec. 14, 1971 I Original application Apr. 8, 1968, Ser. No. 719,474, now Patent No. 3,548,065, dated Dec. 15, 1970. Divided and this application Feb. 2, 1970, Ser. No. 7,522

TIME-POINT GENERATOR 6 Claims, 9 Drawing Figs.

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[56] References Cited UNITED STATES PATENTS 2,559,499 7/1951 Gillette et al. 328/l 80 X 3,358,068 12/1967 Campbell, Jr. 328/62 X Primary Examiner--Donald D. Forrer Assistant Examiner-John Zazworsky An0rneyHill, Sherman, Meroni, Gross & Simpson ABSTRACT: A time-point generator includes a polystage multivibrator for producing pulse signals of a predetermined frequency and spacing, a logic sequencer controlled by said multivibrator, means connected to the multivibrator for changing the spacing of some of the pulses, and gating means controlled by the output of the mult ivibrator and by the output of the logic sequencer, the time-point generator being disclosed as forming part of an automatic rhythm device.

Patented Dec. 14, 1971 3,628,157

6 Sheets-Sheet 5 INVENTOR Freezzzazz ATTORNEY Patented Dec. 14, 1971 3,628,151

6 Sheets-Sheet 5 U7 INVENTOR ATTORNEY TIME-POINT GENERATOR RELATED APPLICATION This application is a division of my copending application, Ser. No. 7l9,474 filed Apr. 8, I968 on an Automatic Rhythm Device, now U.S. Pat. No. 3,548,065.

I. Field of the Invention This invention is directed to a new and improved pulsegenerating circuit arrangement such as for a rhythm-producing sound device.

2. Description of the Prior Art I-Ieretofore, automatic rhythm devices included electronic clock means which would produce evenly spaced pulses to drive ring or binary counters of a fixed number of stages. The proper pattern of pulses for producing rhythmic patterns were then obtained by gating the proper pulses from the chain each time the counter cycled. A large number of evenly spaced pulses had to be included in the cycle in order to permit all the desired patterns to be obtained.

SUMMARY OF THE INVENTION The time-point generator comprises a multistage multivibrator which generates pulses to control the rate and timepoints, such as for use in a rhythm device. The frequency and time spacing of the output pulses of the multistage multivibrator are adjustable. The output of the multistage multivibrator is delivered to a logic sequencer through a plurality of pulse amplifiers. The logic sequencer is a five-stage device with feedback from the last stage to the first stage to repeat the cycle. A number of gating circuits are controlled by the multivibrator and by the logic sequencer.

ON THE DRAWINGS FIG. I is a block diagram showing generally the circuit arrangement of a time-point generator as embodied in a rhythm sound-producing device, constructed in accordance with the principles ofthe present invention.

FIG. 2 is divided into two segments designated FIGS. 2a and 2b and shows a detailed schematic diagram of the circuit arrangement of the time-point generator and logic gate of FIG.

FIG. 3a is a graphical representation of a time-point pulse pattern produced by the time-point generator of FIG. 2;

FIG. 3b is a graphical representation of an alternate timepoint pulse pattern which may be obtained by the time-point generator of FIG. 2 when the triplet switch is closed;

FIG. 4 is a detailed schematic diagram of the resistor matrix used to connect the output of the time-point generator of FIG. 2 to the input of the sound generators of FIG. 3; and

FIGS. 5, 6, and 7 illustrate some of the switching arrangement used for selectively connecting certain portions of the matrix of FIG. 4 to certain input terminals of the sound generators of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Shown in FIG. I is a rhythm sound-producing device which includes a time-point generator 10, constructed according to this invention, which produces a plurality of sequential spaced-apart pulses which may correspond to the sequential spacing of a line or bar of written music. The time-point generator is a general purpose device, and the description of it as part of an automatic rhythm device is only exemplary. The time-point generator 10 includes a polystage, namely a fivestage, multivibrator II, the frequency of which is selectively variable by a potentiometer 12. The potentiometer 12 together with a resistor 14 forms a voltage divider network 13.

The output of the five-stage multivibrator ll is delivered to a logic sequencer and to certain ones ofa plurality oflogic gate circuits designated generally by reference numeral 18. A switch 19 is connected to the five-stage multivibrator II to selectively change the voltage applied to a portion of the multivibrator 11 thereby changing the dimensioning of the multivibrator 11 to cause different pulse width to be generated from certain stages thereof. The output of the five-stage multivibrator 11 is delivered to certain ones of the plurality of logic gate circuits l8 and to the input terminals of the logic sequencer 20.

The five-stage multivibrator 11 forms a clock generator which controls the function of the rhythm device. A clock generator so formed in accordance with this invention can selectively produce evenly or unevenly spaced pulse signals to provide a plurality of different kinds of pulse patterns corresponding to the different kinds of musical arrangements.

Also, according to the present invention, the logic sequencer 20 is a direct-coupled self-biasing circuit which, in the preferred embodiment, has five stages. The multistage multivibrator and/or the logic sequencer of the present invention may have more or less than five stages.

The logic sequencer 20 is biased such that four of the five stages are conducting in the saturated mode of operation and one of the stages is nonconductive. Pulses from the five-stage multivibrator 11 will cause the nonconductive stage to become conductive and the next preceding stage to become nonconductive. Connected to the five-stage multivibrator and to the logic sequencer 20 is a reset switch 21.

The output pulses produced by the .logic gate circuits I8 together with pulses from the multivibrator II and logic sequencer 20 are delivered to a matrix assembly 23. The matrix assembly 23 consists primarily of resistors which are direct current coupled to the output circuits of the time-point generator I0.

The output of the matrix assembly 23 is connected to a selector switch assembly 26 and therefrom to an instrument sound generator 27. The selector switch 26 provides means to connect the proper points of the matrix assembly 23 to selective ones of a plurality of instrument drive circuits 28 of the instrument sound generator 27. The instrument drive circuits 28 are connected to one or more of a plurality of instrument sound generator circuits 29 to activate the generator circuits to produce the sound corresponding to the frequency and wave shape generated by the instrument generators. The outputs of the instrument generators are then applied to a mixing amplifier designated generally by reference numeral 30.

Also associated with the instrument drive circuits 28 are manual selector switches 24 which comprise a plurality of individually selectable switches to actuate the instrument sound generators 29 associated with the switches 24. Therefore, in addition to generating a plurality of different rhythmic sounds in accordance with the output of the time-point generator 10, sounds may be produced by a player operating the manual selectorswitches 24.

The output of the mixing amplifier 30 is connected to a suitable audio amplifier and speaker system (not shown) by means of a cable 31 which has a phone jack 32 connected at one end thereof. The other end of the cable 31 is connected to a potentiometer 33 which serves as a volume control.

FIGS. 2a and 2b are a detailed schematic diagram of the time-point generator 10, of FIG. 1, and is divided into two segments, FIG. 2a and FIG. 2b. The term FIG. 2 is used herein to refer to FIGS. 2a and 2b collectively, i.e., as a single drawing. The five-stage multivibrator 11 includes five transistors 40, 41, 42. 43, and 44. Connected to the collector electrode of each of the transistors 40, 41, 42, 43, and 44 are resistors 45, 46, 47, 48, and 49 respectively. The emitter electrode of each of the transistors 40-44 is connected to ground potential.

The movable contactor of potentiometer 12 is connected to a line 50 which, in turn, is connected to the collector electrode of transistor 40 through a resistor 51 and a capacitor 52. Also connected in line 50 is the collector electrode of transistor 41 through a resistor 53 and a capacitor 54, while the collector electrode of transistor 42 is connected to line 50 through a resistor 55 and a capacitor 56. Similarly, the collector electrode of transistor 43 is connected to line 50 through a resistor 57 and a capacitor 58 while the collector electrode of transistor 44 is connected to line 50 through a resistor 59 and a capacitor 60. A resistor 61 has one end thereof connected between i the junction of resistor 51 and capacitor 52 and the other end thereof connected to the base electrode of transistor 44. A resistor 62 has one end thereof connected between the junction of resistor 53 and capacitor 54 and the other end thereof connected to the base electrode of transistor 40. A resistor 63 has one end thereof connected between the junction of resistor 55 and the capacitor 56 and the other end thereof connected to the base electrode of transistor 41. Similarly, a resistor 64 has one end thereof connected between the junction of resistor 57 and capacitor 50 and the other end thereof connected to the base electrode of transistor 42, and a resistor 65 has one end thereof connected to the junction of resistor 59 and capacitor 60 and the other end thereof connected to the base electrode of transistor 43. Therefore, the output of each of the transistors 40-43 is'resistor capacitor coupled to the input, or base electrode, of the next stage of the five-stage multivibrator. Also, resistors 61-65 are connected to line 50 through resistors 51, 53, 55, 57, and 59 to apply the proper operating bias on the base electrodes of transistors 40-44.

The triplet switch 19 includes a pair of switch blades which are connected to resistors 66 and 67. A lead line 68 is connected to line 50 to supply 13+ for the triplet timing of the fivestage multivibrator 11. In operation, when the triplet switch 19 is in the closed position, a positive voltage is applied through resistors 66 and 67 to change the bias at certain points of the five-stage multivibrator, thereby changing the pulse dimensioning produced by the vibrator.

A cross coupling and threshold circuit is connected between the output of transistor 40 and the input of transistor 41 and includes a capacitor 70 connected in series with a diode 71 and a resistor 72 which are connected in parallel. Similarly, a cross coupling and threshold circuit is connected between the output of transistor 41 and the input of transistor 42 and includes a capacitor 72 connected in series with a diode 74 connected in parallel with a resistor 75. The output of transistor 42 is connected to the input of transistor 43 through a capacitor 76 which is connected in series with a diode 77 connected in series with a resistor 78. Similarly, the output of transistor 43 is connected to the input of transistor 44 through a capacitor 79 connected in series with a diode 80 which, in turn, is connected in series with a resistor 81. The output of transistor 44 is connected to the input of transistor 40 through the cross coupling threshold circuit comprising capacitor 82 connected in series with a diode 83 which, in turn, is connected in parallel with a resistor 04. The cross coupling and threshold circuits connected between each of the five stages of the five-stage multivibrator provides the proper cross-coupling feedback and operating characteristic of each of the stages. For example, each of the diodes 71, 74, 77, 80, and 83 is preferably a germanium diode having a low threshold.

The reset switch 21 includes a pair of contactors 21a and 2 lb. The contactor 21a is connected to ground potential while the contactor 21b is connected to a positive l7-volt source. When the rest switch 21 is closed, ground potential is applied to the cathodes of a pair of diodes 86 and 87 connected end to end. This action will apply ground potential to the junction of resistor 51 and capacitor 52 which action will reset the fivestage multivibrator to a predetermined condition, for example, transistor 44 nonconductive while transistors 40-43 remain conductive.

The five-stage multivibrator 11 is a free-running multivibrator operating such that the output of one stage is coupled to the input of the next succeeding stage and so on. Accordingly, the five-stage multivibrator 11 of the present invention provides a unique and novel means for generating pulse signal information at predetermined time-points to control the operation of the rhythm-producing sound device of the present invention.

The output of transistor 40 of the five-stage multivibrator 11 is coupled to a pulse amplifier 90 through a resistor 91 and a capacitor 92. Similarly, the output of transistor 41 is coupled to a pulse amplifier 93 through a resistor 94 and a capacitor 95, and the output of transistor 42 is coupled to a pulse amplifier 96 through a resistor 97 and a capacitor 98. Similarly, the output of transistor 43 is coupled to a pulse amplifier 99 through a resistor 100 and a capacitor 101 while the output of transistor 44 is coupled to a pulse amplifier 102 through a resistor 103 and a capacitor 104. All of the pulse amplifiers 90, 93, 96, 99, and 102 are constructed in a similar manner and, therefore, a description of only pulse amplifier 90 will be given.

The collector electrode of transistor 90 is connected to a positive voltage source through a resistor 106 while the base electrode thereof is connected to the positive voltage source through a resistor 107. Also connected to the base electrode of transistor 90 is the positive potential from the reset contactor 21b through a resistor 108. The resistor 107 has a resistance value greater than the resistor 108 thereby affording a different value of bias to the base electrode of the transistor 90 than would be applied to the base electrode of transistor 90 when the reset switch 21 is closed. For example, the resistor 107 may have a value four times greater than the resistor 108. When the reset switch 21 is closed, each of the transistors 90, 93, 96, 99, and 102 are rendered conductive in the saturated mode of operation, thereby applying substantially ground potential to the output of each of the pulse amplifiers.

The output of pulse amplifiers 90, 93, 96, 99, and 102 is applied to certain ones of the terminals of the matrix assembly 23, is is more fully described hereinbelow. The outputs 1, 2, 3, 4, and 5 enclosed in circles correspond to similarly marked terminals at the input of the matrix assembly 23. Therefore, the output of the pulse amplifiers is direct current coupled to the matrix assembly 23. Also connected to the output of pulse amplifiers 90, 93, 96, 99, and 102 are capacitors 109, 110, 111, 112, and 113 respectively. The capacitor coupled pulses from the output of the pulse amplifiers are delivered to certain ones of the logic gate circuits 18, of FIG. 1. The outputs of pulse amplifiers 90, 93, 99, and 102 are direct current coupled to the inputs of the logic sequencer 20. No direct current coupling is provided between the pulse amplifier 96 and the logic sequencer 20.

A cymbal decay control circuit is connected to the pulse amplifier 90 and includes a transistor 114 having the base electrode thereof connected to the pulse amplifier 90 through a diode 115 and a resistor 116. Connected between the junction of diode 115 and resistor 116 is a capacitor 117. The collector electrode of the transistor 114 is connected to an output lead, indicated by 11] positioned within a circle, through a resistor 118. Also connected to the resistor 118 isa capacitor 119, a resistor 120 anda diode 121. The resistor 120 and a diode 121 are connnected in parallel and in series with a capacitor 122 which, in turn, is connected to ground potential.

The DC coupling from the pulse amplifiers 90, 93, 99, and 102 are direct current coupled to the logic sequencer 20 through resistors 126, 127, 128, 129, and 130. It will be noted that the resistors 127 and 128 are connnected together to the common output of the pulse amplifier 93.

The resistors 126, 127, 128, 129, and 130 are connected to the five stages of the logic sequencer 20, and more specifically the base electrode of transistors 131, 132, 133, 134, and respectively, Also connected to the resistors 126 130 is a resistor coupling and biasing network 136a which means for interconnecting selected outputs of transistors 131-135 to selected inputs of the same transistors as shown to provide proper interaction between transistors 131-135 to function as a logic sequencer.

The transistors 131 has the collector electrode thereof connected to a positive voltage source through a resistor 136, while the transistor 132 has the collector electrode thereof connected to the positive voltage source through a resistor 137. Similarly, the transistor 133 has the collector electrode thereof connected to the positive voltage source through a resistor 138, and the transistor 134 has the collector electrode thereof connected to the positive voltage source through a resistor 139 while the collector electrode of the transistor 135 is connected to the positive voltage source through a resistor 140. The collector of the transistor 131, on which the output pulse appears, is connected to certain ones of the logic gate circuits 18 and to the base electrode of transistor 132 through a capacitor 111 and a resistor 142. The output terminal or collector of the transistor 132 is connected to certain ones of the logic gate circuits 18 and to the base electrode of the transistor 133 through a capacitor 143 and a resistor 144. The output terminal or collector of the transistor 133 is connected to certain ones of the logic gate circuit 18 and to the base electrode of the transistor 134 through a capacitor 145 and a resistor 146. The output terminal or collector of the transistor 134 is delivered to certain ones of the logic gate circuits 18 and to the base electrode of the transistor 135 through a capacitor 1 17 and a resistor 1413. The last stage, the transistor 135, has its output terminal or collector connected to the first stage, the transistor 131, through a capacitor 149 and a resistor 1511. Therefore, the logic sequencer will continue to repeat the cycle of operation each time the transistor 135 produces an output pulse. All but one of the transistors 131-135 are conductive in the saturated mode of operation. A pulse from one of the pulse amplifiers 90, 93, 99, and 102 will render the nonconductive transistor of the logic sequencer 20 conductive and. while the nonconductive transistor is becoming conductive, it will produce a pulse which will render the next succeeding transistor of the sequencer 20 nonconductive.

The output of the logic sequencer 20 is delivered to certain ones of the logic gate circuits 18. The logic gate circuits 18 comprise a plurality of transistors 151, 152, 153, 154, 155, I56, 157, 1511, 159, 160, 161. and 162 which have the base electrodes thereof direct current coupled to the outputs of the logic sequencer 20 and capacitive coupled to the outputs of the pulse amplifiers 90, 93, 96, 99, and 102.

All of the logic gate circuits transistors 151-162 operate in the same manner and, therefore, only one transistor stage is described. The transistor 152 has the collector electrode thereof connected to a l7-volt positive source through a resistor 163 and the base electrode thereof connected to the positive voltage source through a resistor 164. The emitter electrode of each of the transistors 151-162 is connected to ground potential. Also connected to the base electrode of the transistor 152 is a plurality of resistors 166, 167, and 168. The resistor 166 is connected to the collector electrode of the transistor 132 of the logic sequencer 20 while the resistor 167 is connected to the collector electrode of the transistor 134 of the logic sequencer 20. The resistor 168 is connected to the output ofthe pulse amplifier 90 through capacitor 109.

The logic transistor 152 operates an an NAND logic requiring (1) that either one of transistors 132, 134 of the logic sequencer 211 to be conductive, and (2) a pulse from the pulse amplifier 91). Only the transistors 152, 153, 154, 155, 156, 157, 158. 159. and 160 operate as NAND gates requiring a pulse from the logic sequencer 20 and a pulse from one of the pulse amplifiers. The transistor 156 of the logic circuit operates as a pulser in response to a negative signal at the output of the transistor 134 of the logic sequencer 20. The transistors 151 and 162 of the logic gate circuits 18 operate as OR logic requiring a signal at either one or the other of the pair of transistors connected between the base electrode thereof and the logic counter 20.

According to the present invention, each of the pulse amplifiers 90, 93, 96, 99, and 102 as well as each of the conducting stages of the logic sequencer and the transistors of the logic gate circuits 18 are operated in the saturated mode of operation and produce output signals when the transistors are cut off for a short period of time. Furthermore, by operating the transistors in the saturated mode of operation direct current coupling between stages is possible thereby simplifying the circuit arrangement and reducing the number of components necessary for the operation thereof. Additionally, the present invention provides cross-coupling means between the stages of the five-stage multivibrator 11 which a capacitor and a diode resistor network to insure that each transistor will be cut off quickly when the next succeeding transistor in the stage is rendered conductive.

A downbeat circuit is provided and connected to the output of transistor 161 of the logic gate circuits 18. The downbeat circuit includes a pair of transistors 171) and 171 which operate as a one-shot multivibrator with the transistor 170 normally nonconductive and the transistor 171 conductive. A pulse from the transistor 161 through a resistor 172 will render the transistor 170 conductive thereby energizing an indicating lamp 173. The downbeat circuit will cause the indicating lamp to become deenergized automatically in response to the operation of the one-shot multivibrator. The lamp 173 is used as s downbeat indicator for a person who is using the rhythm sound device for accompaniment.

Shown in FIG. 3a is a time-point pulse pattern of the various output signals developed at the output terminals of the timepoint generator 18 of FIGS. 2a and 2b. The horizontal direction of the wave pattern represents time and is divided into a two-bar pattern. The scale near the top of the Figure divides the two-bar pattern into 32 notes which are represented by the number series (L31. Therefore, each bar is divided into l6 evenly spaced notes. However, as shown by the output signals from outputs@,@ and@ the time-point pulses are generated only at certain times corresponding to selected notes of each bar.

The output NC. is a gate pulse which is initiated by output@ and terminated by output@ Although the gate pulse NC. is not used for the particu r musi l arrangements described herein, the logic pulses Q and Q are used. The gate pulse N.C. can be used, when esired, or other musical arrangements. At the termination of gate pulse N.C., the gate pulse@ is initiated and pulseis terminated by the second@pulse. At the termination of gate pulse, pulseOis initiated which, in turn, is terminated by the third @pulse. Termination of gate pulse @will initiate gate pulse@ and the fourth@ pulse will terminate this gate. Finally, termination ofgate pulse will initiate gate pulsewhich, in turn, is terminated by the first pulse and the cycle of the logic sequencer is repeated.

. v loped at e outputs of the logic gates 18 are the pulses Q; Q and As seen in FIG. 2b, output pulses 1 are develope at the output oftransistor 151 and outputs and Q are develop at transistor 162. 56 deve ops the output The nomenclature T ansistor 9 means the first pulseduring the lrsycle of the five- 5 age multivibrator 11. The nomenclature means the fifth pulse @during the first cycle of the multiv rator 11, and so on. i

A novel feature of the prese inv tio is t 'tthe co bined pulse pattern of pulses 15?, and Q produces the clave pattern whic is s own at the bottom of FIG. 3a. This clave pattern is obtained directly without the use of special or added logic circuits which would have no other function. The calve pattern is used in the production of many Latin rhythms and other musical arrangements and, therefore, is very desirable.

Shown in FIG. 3b is the tirne-point pulse pattern obtained from the output of the time-point generator 10 when the triplet switch 19 is closed. Closure of the switch 19 decreases the time spacing between theandpulses of the five-stage multivibrator. Therefore, each bar of music is divided into a l2-musical note scale indicated by the series of numbers 0-11 and 12-23. As mentioned with regard to FIG. 3a, there are four cycles of the five-stage multivibrator for each cycle of the logic sequencer 20, the only difference being the time spacing between certain pulses. Accordingly, the novel circuit arrangement of the time-point generator 20 of the present invention provides means for obtaining different time-point pulse patterns without requiring additional circuitry.

Shown in FIG. 4 is the detailed arrangement of the matrix assembly 23. The vertical row of terminals is arranged for connection to the circuit points which have the same number designation on the time-point generator of FIG. 2 and the horizontal row of terminals is arranged for connection to terminal points of the sound generator 27 of FIG. 1 through the selector switches 26. For example, a signal at terminalof the vertical row of terminals will produce a corresponding pulse at a plurality of terminals indicated by the number (D in the horizontal row of terminals.

Also, it will be noted that the matrix assembly 23 of FIG. 4 has relatively few diodes associated therewith thereby decreasing the relative cost of the matrix as well as the complexity thereof. This is accomplished by the fact that the output of the time-point generator is operated in a saturated mode of operation.

Shown in FIG. 5 is one switch arrangement for selecting a predetermined number of terminal points from the horizontal row of terminals of the matrix of FIG. 4 for connecting these terminal points to the desired input terminals of the sound generator 27 of FIG. 1. FIG, 4 shows the preferred switch arrangement for bossa nova sound. A switch 300 includes a plurality of ganged together contactors having certain ones thereof connected to the selected terminals of the horizontal row of terminals of FIG. 4. The output terminals of the switch 300 are connected to terminals of the sound generator 27 having the same letter designation.

FIG. 6 illustrates a switching arrangement between the horizontal row of terminals of the matrix of FIG. 4 and the sound generator 2'] of FIG. I and includes a switch assembly 301. The switch assembly 301 is connected to selected terminals of the horizontal row of terminals of the matrix of FIG. 4 and to selected terminals of .the sound generator 27 so as to produce a samba rhythm. Similarly, the input terminals of switch 301 are connected to the terminals of the horizontal row of terminals of FIG. 4 having the same designation.

FIG. 7 shows still a further switching arrangement for producing a rhumba sound from the automatic rhythm device utilizing the present invention. The switch arrangements shown in FIGS. 5,6, and 7 arejust a few of the switch arrangements of the selector switch 26 of FIG. I. Furthermore, it will be understood that the triplet switch 19 of FIGS. 1 and 2a is associated with certain ones of the switches of the selector assembly 26 to change the spacing of the time-point pulse pattern produced by the time point generator 10. For example, selector switches for developing the slow fox, swing and Dixie musical arrangements would also include switch contacts similar to switch 19 to apply 8+ to the five-stage multivibrator through resistors 66 and 67. The closing of switch 19 would change the time-point pulse pattern from that shown in FIG. 3a to that shown in FIG. 312.

A detailed description of the matrix assembly of FIG. 4 as well as the switch arrangements of FIGS. 5, 6, and 7 is not given as it is believed that the circuit arrangement illustrated is self-explanatory and teaches those skilled in the art how to practice the invention.

Accordingly, the present invention provides unique and novel means for generating clock pulses at predetermined time-points in a simple and straightforward manner. Accordingly, variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.

1 claim as my invention:

ll. A time-point generator, comprising: a polystage multivibrator, having at least one output terminal for each stage, for producing pulse signals of a predetermined frequency and spacing; a logic sequencer having input terminals connected to the output terminals of said polystage multivibrator for receiving said pulse signals and output terminals on which said signals periodically appear; and means connected to said polystage multivibrator for selectively changing the spacing between at least some of the pulses of said pulse signals.

2. A time-point generator according to claim 1 wherein said polystage multivibrator is a five-stage multivibrator, said logic sequencer being a five-stage logic sequencer, the stages of said logic sequencer having input terminals respectively connected to the output terminals of said five-stage multivibrator.

3. A time-point generator according to claim I including a plurality of pulse amplifier circuits respectively connected between each output terminal of said polystage multivibrator and the input terminals ofsaid logic sequencer.

4. A time-point generator according to claim I including a plurality of logic gate circuits each having an input terminal connected to certain output terminals of said logic sequencer and to certain output terminals of said polystage multivibrator.

5. A time-point generator according to claim 1, each stage of said multivibrator having an input terminal connected by a cross coupling network to an output terminal of another stage to form a continuous series of stages, said cross-coupling network consisting of a capacitor connected in series with a resistor and a diode connected in parallel with said resistor.

6. A time-point generator comprising: a multivibrator having at least three stages with output terminals for producing a plurality of pulse signals of a predetermined frequency and spacing; a logic sequencer having input terminals connected to the output terminals of said multivibrator for receiving said plurality of pulse signals and further having output terminals; and gating means connected to the output terminals of said multivibrator and to the output terminals of said logic sequencer for being controlled by said multivibrator and by said logic sequencer.

UNITED STATES PATENT oTTIcE- CERTIFICATE OF CORRECTEQN Patent No. 3,628, 157 Dated December 14, 1971 Inventor(s) Alfred B. Freeman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover page, insert [73] Assignee z Chicago Musical Instrument Co. Chicago, Ill

C01. 2, line 69, change "in" to --to--;

Col. 3; line 36, change "72" to Q73;

Col. 3, line 57, change 'rest" to --re set--; I

COL 4, line 28, change "is is" to was is s Col. 5, line 49, change "an an" to' -as an;

Col. 5, line 74, after "which" insert includes-"q Col. 6, line 14, change "as s to was a;

COL. 6, line 54, change "calve" to wclave Signed and sealed this 22nd day of August 1972.

(SEAL) Attest:

EDWARD MELETGIERJR. ROBERT GOTTSCHALK Atte sting Officer Commissioner of Patents FORM PO-105O (10-69) USCOMM-DC 60376-P69 w u.s GOVERNMENT PRINTING OFFICE i969 0-366-334 nnirnn s'mrns ATENT crricn @ERTWMATE 1 @QRWYMN Patent No. 3,628,157 Dated December 14,, 1971 Inventor(s) Alfred B. Freeman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover page, insert WW3] Assignee: Chicago Musical Instrument C0,, Chicago, 111.

C010 2, line 69, change "in" to wtom;

Col 3, line 36, change "'72" to w'BM;

Col, 3, line 57 change "rest" to Mreset C010 4, line 28, change "is is" to was isma;

C01 5, line 49, change "an an" to' as an C011, 5, line '74, after "which" insert minciudes-a;

C010 6, line 14, change as s to was am;

Coir n, line 54, change "calve' to mclave n Signed and sealed this 22nd day of August 1972.

(SEAL) At test:

EDWAH) i ini Lll lTCiHiiRflfio ROBERT GGTTSCHALK Atte sting Officer Commissioner of Patents F ORM PC4050 (10-69) USCOMM-DC 50376-P69 Q U.Sv GOVERNMENT PRINTING OFFICE: I969 O-366-33i V UNITED STATES PATENT OFFICE- CERTIFICATE OF CORRECTION Patent No. 3,628, 157 Dated December 14, 1971 Inventor(s) Alfred B. Freeman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover page, insert [73] Assigneez Chicago Musical Instrument Co. Chicago 111.

Col. 2, line 69, change "in" to --to--;

Col. 3; line 36, change "72" to .-73--;.

Col. 3, line 57, change "rest" to reset;

Coin 4, line 28, change "is is" to "as 1e...;;'

Col. 5, line 49, change "an an" to as an";

C01,. o, line 74, after "which" insert includes- Col. 6, line 14, change "as s" to as a;

(301.. 6, line 54, change "calve" to h clave Signed and sealed this 22nd day of August 1972.

(SEAL) Attest:

EDWARD TLFLETGHERJB. ROBERT GOTTSCHALK. Attefiitlilg Officer Commissioner of Patents FORM PC4050 (10-69) USCOMM-DC 5O376-P69 U 5. GOVERNMENT PRINTING OFFICE: \959 O366-33A 

1. A time-point generator, comprising: a polystage multivibrator, having at least one output terminal for each stage, for producing pulse signals of a predetermined frequency and spacing; a logic sequencer having input terminals connected to the output terminals of said polystage multivibrator for receiving said pulse signals and output terminals on which said signals periodically appear; and means connected to said polystage multivibrator for selectively changing the spacing between at least some of the pulses of said pulse signals.
 2. A time-point generator according to claim 1 wherein said polystage multivibrator is a five-stage multivibrator, said logic sequencer being a five-stage logic sequencer, the stages of said logic sequencer having input terminals respectively connected to the output terminals of said five-stage multivibrator.
 3. A time-point generator according to claim 1 including a plurality of pulse amplifier circuits respectively connected between each output terminal of said polystage multivibrator and the input terminals of said logic sequencer.
 4. A time-point generator according to claim 1 including a plurality of logic gate circuits each having an input terminal connected to certain output terminals of said logic sequencer and to certain output terminals of said polystage multivibrator.
 5. A time-point generator according to claim 1, each stage of said multivibrator having an input terminal connected by a cross coupling network to an output terminal of another stage to form a continuous series of stages, said cross-coupling network consisting of a capacitor connected in series with a resistor and a diode connected in parallel with said resistor.
 6. A time-point generator comprising: a multivibrator having at least three stages with output terminals for producing a plurality of pulse signals of a predetermined frequency and spacing; a logic sequencer having input terminals conNected to the output terminals of said multivibrator for receiving said plurality of pulse signals and further having output terminals; and gating means connected to the output terminals of said multivibrator and to the output terminals of said logic sequencer for being controlled by said multivibrator and by said logic sequencer. 